An integrated circuit (IC) die typically includes a substrate of semiconductor material, such as silicon, with a flat top surface and an opposite flat bottom surface. A metal circuit layer is usually provided only on the top surface of the semiconductor substrate. The circuit layer generates heat when the die is operating. Various techniques have been used to dissipate the heat generated by the metal circuit layer. Typically only a very small portion of the heat from the circuit layer is dissipated through the semiconductor substrate because semiconductors are poor heat conductors.